However, none of the four patients had any premonitory soft tissue masses or swelling. One of these four cases was a patient who is

a phenotypic and genotypic variant of FOP (patient 7). The other three had classic FOP. In 31% of patients (22/72 cases), the initial onset of FOP occurred following trauma. In 18 of the 22 cases, the onset occurred following blunt trauma during routine childhood play; in 4 of the 22 cases, the onset occurred APO866 mouse after surgical biopsy of an unsuspected FOP lesion. Most of the parents could not recall the definitive time interval between the blunt trauma and the resulting flare-up. Only in six patients was the interval clearly remembered by their parents to be one week (three cases), ten days (one case), two weeks (one case), and three weeks (one case). The trauma experienced by these 22 patients included blunt trauma

to the occipital region, back of neck, shoulder or elbow, and surgical procedures for torticollis, congenital hip dysplasia, osteochondroma of the proximal medial tibia, and fracture of the femoral shaft. In all the 22 patients, spontaneous flare-up would occur subsequent to the trauma-induced onset. The spatial progression of FOP lesions was similar to that previously reported [3]. There was no predictable interval between flare-ups for those affected with spontaneous Inhibitor Library order onset or for those who had spontaneous flare-ups following an initial post-traumatic flare-up. Eighty-four percent of patients (61/72 cases) were misdiagnosed or had not been given any diagnosis in local hospitals prior to their visit to our clinic or our visit to their home. Thirty-six percent of patients (26/72 cases) had undergone a diagnostic biopsy of an FOP lesion prior to the definitive diagnosis of FOP. One hundred percent of those patients (26/26) developed heterotopic ossification at the operative site as a result of the biopsy. The pathological findings were dramatically

different from patient to patient and reflected both Pyruvate dehydrogenase the stage of the lesion at the time of the biopsy and the ignorance of the medical team regarding the true cause of the pathology. Pathologic misdiagnoses occurred in 92% of patients (24/26 cases) and included panniculitis, eosinophilic fasciitis, fibromyoma, nodular fasciitis, benign fibroma, aggressive fibroma, rhabdomyosarcoma, chondroma, osseous fasciitis, and osteochondroma. 8% of patients (2/26 cases) were correctly diagnosed with FOP on the basis of the pathologic findings and the associated toe malformations. Unfortunately, FOP could have been diagnosed in all cases on the basis of malformed toes and soft tissue swelling and/or heterotopic ossification before an unnecessary and invasive biopsy had been performed [4].